Many numbers acquired special arithmetic or mystical meaning back in ancient times. Nowadays, these ideas have been transformed into something else, and the same numbers have been “overgrown” with new myths. Moreover, new numbers were invented, some of which received a first name, while others received a surname. Today we can talk about natural, integer, real, rational, irrational, imaginary, transcendental, transfinite and many other numbers. From this book you will learn what numbers meant in ancient times and what wonderful properties they have acquired in the modern world.